光变周期 meaning in English
period of light variation
Examples
- Well , you may ask : how can we determine the luminosity - period relation
但你可能会问：我们怎样得知造父变星的光变周期光度关系？ - Their periods , in the range of a few days to a few months , have a definite relation with the luminosities
最特别的是，它们的光变周期和光度有直接的关系，周期越长，亮度越大。 - Subsequently astronomers found more and more cepheids in different corners of the universe and discovered that there exists a simple relationship between their luminosities and light variation periods
其后的天文学家在宇宙不同角落陆续找到其他造父变星，并发现了它们光度跟光变周期间的简单关系。 - This usually means that we find out the relation using stars near us , then apply the relation to greater distances . in general , we use accurately determined distance indicators for small distance to calibrate distance indicators for greater distances
事实上，科学家首先找一些离我们较近的造父变星，找出它们的光变周期与光度的关系，然后假设这个关系对遥远的同类变星依然适用。 - We have to use some other methods to measure the luminosity or equivalently the absolute magnitude of the cepheid variable . since we can readily measure the apparent magnitude of a cepheid variable , to measure the luminosity means measuring the distance . we use some distance measurement methods , for example , parallax , to determine the relation
要弄清这个关系，我们要知道不同造父变星的光度和光变周期数据，量度光变周期当然不是问题，但要得知一颗恒星的光度，我们首先要得知它的距离，这时便须借助好像视差法等其他量度天体距离的方法。